1. Field of the Invention
The present invention relates to a gas pressure-reducing valve and, more particularly, to a gas pressure-reducing valve in which a valve member to be seated on a valve seat having a valve hole opened at its central portion and leading to a pressure-reducing chamber between a body and a diaphragm is fixed on a valve stem coaxiaily extending through the valve hole, and in which the valve stem is fastened to a fastened member fixed on the central portion of the diaphragm.
2. Related Art
Such a gas pressure-reducing valve has already been known in the prior art from Japanese Patent Application Laid-open No. 8-334182.
In the arrangement of the prior art, however, the fastened member fixed on the central portion of the diaphragm is provided with only a threaded bore opened toward the valve stem and an externally threaded portion formed on the end portion of the valve stem on the diaphragm side is screwed in the threaded bore. As a result, chips may be produced when the externally threaded portion is screwed in the threaded bore so as to connect the valve stem to the diaphragm. Here, the position of the valve stem fastened to the fastened member is located in the vicinity of the valve seat so that reliable seating of the valve member on the valve seat is obstructed when the chips stick to the valve seat. This makes it necessary to remove the chips at the time of assembling the pressure-reducing valve, therefore the assembling works become complicated.